1. Field of the Invention
The present invention relates to an apparatus for and a method of bundling a plurality of electric wires, and in particular to an apparatus for and a method of automatically bundling wires which have been cut into a predetermined length and placed on a tray, then removing them from the tray.
2. Description of the Related Art
Conventionally, electric wires are cut into a predetermined length and crimped with terminal fittings at their ends by an automatic wire cutting and terminal crimping machine, then placed on a receiving tray. After these processes have been performed, the terminal-crimped wires are bundled in a predetermined quantity and removed from the tray for the next process. An example of a conventional wire bundling apparatus that automatically performs these processes is disclosed in Japanese Laid-Open Patent Publication No. 5-229519.
In such application, as shown in FIG. 10(A), the wire bundling apparatus is provided with a bundling pawl mechanism 2 disposed laterally of the receiving tray 1. The bundling pawl mechanism 2 has a pair of upper and lower pawl members 5a, 5b that move toward and away from each other upon actuation of cylinders 3, 4. As shown in FIGS. 10(B) and 10(C), the upper and lower pawl members 5a, 5b enclose and bundle the wires W positioned on the tray 1, and then remove them from the tray 1 by rotating the bundling pawl mechanism 2 while actuating another cylinder provided as a rotating mechanism (not shown).
However, a problem with the conventional bundling apparatus of this type is that some of the wires W may be caught in angled inner corners 7 formed by the overlying upper and lower pawl members 5a, 5b during the bundling process as shown in FIG. 10(B), and may become damaged or broken. Another problem is that since the wire bundling operation is done by moving the upper and lower pawl members 5a, 5b toward each other in a closing direction, the pawl members 5a, 5b must be disposed adjacent the tray as illustrated. Because of this, the wires W, which are fed downwardly from a wire feeding mechanism 6 to the tray 1 as shown in FIG. 10(A), may interfere with the upper pawl member 5a, thus resulting in a situation where all the required wires W are not properly fed on to the tray 1. Still another problem is that the wires W dropped from the wire feeding mechanism 6 may lay scattered on the tray 1 because of the momentum they gather while falling. Thus, the pawl members 5a may fail to enclose all the wires W during the bundling operation.
The present invention has been developed after taking the above problems into consideration, and aims to ensure that a pair of pawl members bundles all the required wires to be fed downwardly to the receiving tray, without damaging them.
To solve the above problems, the present invention provides an apparatus for bundling a plurality of wires placed on a receiving plate. The apparatus is provided with a bundling pawl mechanism that includes a plate and a pair of pawl members. The pawl members are respectively supported at pivot points provided on the plate in spaced-apart relation and are interconnected with driving units for opening and closing movement. The pawl members also respectively extend beyond an edge portion of the plate. A wire bundling region is formed between inner surfaces of the pawl members and the edge portion of the plate when at least one of the pawl members rotates toward the other of the pawl members in a closing direction. The bundling pawl mechanism further includes a wire catch prevention member configured to project into the wire bundling region from an angled inner corner formed between the inner surface of the at least one pawl member and the edge portion of the plate when the at least one pawl member rotates in the closing position.
With the above construction, the pair of pawl members are disposed in spaced apart relation, thereby forming a wire accommodating space therebetween, which is large enough to receive all the required wires when they are in an opening condition. Also, since the wire catch prevention member pushes or projects into the bundling region from the angled inner corner, even if the angle of the inner corner becomes acute as the wire bundling region becomes narrower, the wires can be prevented from becoming caught in the angled inner corner, thereby preventing the wires from becoming damaged in the angled inner corner.
According to a preferred embodiment of the present invention, the wire catch prevention member is pivotably supported at a pivot point provided on the plate. The at least one pawl member has an engaging portion that operatively engages and pushes the wire catch prevention member into the wire bundling region when the at least one pawl member rotates in the closing direction. Thus, the projecting or pushing operation of the wire catch prevention member can be done simply by shifting the at least one pawl member in the closing direction.
In another aspect of the present invention, the apparatus further includes a movable frame that supports and moves the bundling pawl mechanism between a retracted position which is located outwardly of the receiving tray and a bundling position which is located below the receiving tray. The bundling pawl mechanism is configured to be lifted from the bundling position to a wire receiving position which corresponds to the receiving tray via a lifting mechanism, so that the pawl members can receive the wires placed on the receiving tray. Preferably, the wire receiving position is laterally adjacent the receiving tray.
With this construction, the pawl members can be disposed in the retracted position away from the receiving tray when the wires are fed downwardly onto the tray. Thus, the wires which are to be fed downwardly can be prevented from interfering with the pawl members, thereby preventing the wires from inadvertently coming out of the receiving tray. Further, the bundling pawl mechanism is shifted to the bundling position below the receiving tray, and then lifted from there. Therefore, the pawl members can shift toward the bundling position without hooking or entangling the wires, and can receive the wires therebetween with certainty, when the bundling pawl mechanism is lifted to the wire receiving position.
In a further aspect of the present invention, the apparatus further includes a rotating mechanism that supports the bundling pawl mechanism so that the bundling pawl mechanism rotates upwardly from the receiving position when the bundling pawl mechanism removes the wires from the receiving tray. With the above construction, since the wires enclosed and bundled by the pawl members can be removed from the receiving tray by rotating the pawl members upwardly, even if the wires hang downwardly from the bundling pawl mechanism, they can be prevented from interfering with surrounding units.
In a further aspect of the present invention, the apparatus further includes a movable frame that supports and moves the bundling pawl mechanism between a retracted position which is located outwardly of the receiving tray and a bundling position which is located below the receiving tray. The at least one pawl member is disposed farther away from the receiving tray than the other of the pawl members in a direction in which the bundling pawl mechanism moves from the retracted position to the bundling position. The at least one pawl member is configured to contact the wires placed on the receiving tray when the bundling pawl mechanism moves to the bundling position, so that the wires can be gathered at one location on the receiving tray. With the above construction, when the bundling pawl mechanism moves to the bundling position, the pawl member disposed farther away from the receiving tray contacts the wires scattered on the receiving tray, and gathers them at one side or location of the receiving tray. Accordingly, the pawl members can enclose and bundle all the required wires with certainty.
Furthermore, the present invention provides a method of bundling a plurality of wires which are to be fed on a receiving plate successively and removing the wires from the receiving tray. The method includes: providing a bundling pawl mechanism having a plate and a pair of pawl members supported on the plate for opening and closing movement; gathering the wires at one location on the receiving tray by moving one of the pawl members into contact with the wires placed on the receiving tray while advancing the bundling pawl mechanism from a retracted position which is located outwardly of the receiving tray to a bundling position which is located below the receiving tray; lifting the bundling pawl mechanism from the bundling position to a wire receiving position which is located laterally adjacent the receiving tray, whereby the gathered wires can be received between the pawl members when the bundling pawl mechanism is lifted; closing the pawl members and forming a wire bundling region between inner surfaces of the pawl members and an edge portion of the plate, thereby enclosing and bundling the wires in the wire bundling region; retracting the bundling pawl mechanism to a position where the pawl members are disposed outwardly of the receiving tray; and opening the pawl members to release and permit removal of the bundled wires. Preferably, the method also includes: providing a wire catch prevention member in an angled inner corner formed between the inner surface of at least one of the pawl members and an edge portion of the plate; and projecting the wire catch prevention member into the wire bundling region from the angled inner corner when the at least one pawl member moves in a closing direction, so that the wires can be prevented from becoming caught in the angled inner corner.
Still furthermore, the present invention provides an apparatus for bundling a plurality of wires placed on a receiving tray. The apparatus is provided with a bundling pawl mechanism that includes a plate having an edge portion and a pair of pawl members pivotably supported on the plate and extending beyond the edge portion. The pawl members forms a wire accommodating region between inner surfaces thereof and the edge portion when the pawl members are positioned away from each other in a opening condition, and forms a wire bundling region between the inner surfaces thereof and the edge portion when at least one of the pawl members rotates toward the other of the pawl members in a closing direction. The at least one pawl member is configured to form an angled inner corner between the inner surface thereof and the edge portion when the at least one pawl member rotates toward the other of the pawl members in the closing direction. The bundling pawl mechanism further includes a wire catch prevention member configured to form an obtuse angle between the inner surface of the at least one pawl member and the edge portion when the at least one pawl member rotates toward the other of the pawl members to enclose and bundle the wires. Accordingly, the wires can be prevented from becoming caught in the angled inner corner, thereby preventing the wires from becoming damaged while the wires are being enclosed and bundled.
In another aspect of the present invention, the wire catch prevention member is configured to project from the angled inner corner into the wire bundling region when the at least one pawl member rotates toward the other of the pawl members in the closing direction. As a result, the obtuse angle can be formed between the inner surface of the at least one pawl member and the edge portion, thereby preventing the wires from becoming caught in the angled inner corner.
In a further aspect of the present invention, the wire catch prevention member is pivotably mounted on the plate between the pawl members provided in spaced-apart relation, and extends to overly the at least one pawl member in intersecting relation. Because of this construction, the wire catch prevention member can be pushed into the wire bundling region when the at least one pawl member rotates toward the other of the pawl members. Preferably, the wire catch prevention is positioned in the inner angled corner when the pawl members are in the opening condition, and rotates into the wire bundling region when the at least one pawl member rotates toward the other of the pawl members while decreasing the angle of the inner angled corner.
According to a preferred embodiment of the present invention, the wire catch prevention member is biased toward the at least one pawl member and away from the other of the pawl members, and the at least one pawl member is configured to push the wire catch prevention member while sliding along the wire catch prevention member when the at least one pawl member rotates toward the other of the pawl members in the closing direction.
In a further aspect of the present invention, the at least one pawl member has an engaging portion that operatively engages and rotates the wire catch prevention member into the wire bundling region when the at least one pawl member rotates in the closing direction. The wire catch prevention member is configured to push the wires toward the center of the wire bundling region during its movement.
In a further aspect of the present invention, the apparatus further includes a movable frame that supports and moves the bundling pawl mechanism from a retracted position to a wire bundling position. The at least one pawl member is configured such that its protruding end contacts and moves the wires placed on the receiving tray when the bundling pawl mechanism shifts toward the wire bundling position, so that the wires can be gathered at one location on the receiving tray.